While not yet confirmed by AT&T, WPCentral reports that the Windows Phone 7.8 updates will begin with the AT&T version of the Nokia Lumia 900. The January 30th roll out date is one day earlier than owners were expecting. Sadly, as of right now, it looks like this phone is the only one that has any type of specific details attached to it as far as the update is concerned.

The AT&T Lumia 900 will gets its Windows Phone 7.8 update next week it seems.

That said, those who do own the AT&T Lumia 900 will be happy to know that in addition to the release date, there is also a substantial change log to look at ahead of the software’s release later in the month.

Here is what Lumia 900 owners have to look forward to come January 30th:

New Start Screen – This change immediately refreshes and updates the look of the customers Nokia Lumia 900. Customers will now have a start screen that is similar to Windows Phone 8. This new start screen provides users with more options to personalize their start screen. More tiles can be pinned to the start screen and their sizes can be altered between small, medium, or large. In addition the wide vertical black zone on the far right called the “gutter” has been removed.

New theme colors – Customers will have even more options to personalize their Lumia 900. A new theme color may be selected from many new colors that have been added to the expanded color pallet.

Bing “Image of the Day” Lock Screen Option: Customers may now enable the regularly changing “Image of the Day” from the Bing search screen to be automatically displayed as their lock screen wallpaper. As a result the customer will have a new lock screen image available on their device each day.

Improved Lock Screen accidental wipe protection: Customers will experience an enhanced lock screen that is less likely to open accidentally by an inadvertent touch on the display. This will help extend the life of the battery for customers who had experienced this issue.

Quality and Security Enhancements – Customers will experience greater device stability with the implementation of multiple software fixes and enhancements. Improved security fixes and enhancements have been made to protect customer information on their device.

API Enhancements – Customers ability to experience the benefit of these new API enhancements will depend on OEM implementation or third party applications that utilize these new APIs. A customer should check the download store after completing the upgrade for new OEM and third party applications. For example: Bluetooth DRM free file transfer API, User data migration API, Convert a local DRM free MP3 file to a ringtone API.

The update is said to be around 100MB in size and users will be able to install it through Zune software on their PC. That means that owners of the Lumia 900 on AT&T will want to set aside some time to install the update to their phone.

Windows Phone 7.8 of course is the update that Microsoft will be rolling out to owners of select devices not running Windows Phone 8. Devices that didn’t come standard with Windows Phone 8 will never get Microsoft’s latest update and instead, will have to make due to Windows Phone 7.8 which brings, amongst other things, the new Start screen found in Windows Phone 8.

We imagine that after the Lumia 900 gets its software update, we should see other devices fall in line soon afterwards though as of right now, many of those release dates remain mysterious.